Nonionic surfactants are generally used in laundry detergent compositions for their ability to remove greasy and oily soils. Cationic surfactants have also been used in detergent compositions, primarily to provide adjunct fabric care benefits, and not for the purpose of cleaning. Certain cationic surfactants have been included in detergent compositions for the purpose of yielding a germicidal or sanitization benefit to washed surfaces; see, for example, U.S. Pat. No. 2,742,434, Kopp, issued Apr. 17, 1956; U.S. Pat. No. 3,539,520, Cantor et al, issued Nov. 10, 1970; and U.S. Pat. No. 3,965,026, Lancz, issued June 22, 1976. Other cationic surfactants, such as ditallowalkyldimethylammonium chloride, are included in detergent compositions for the purpose of yielding a fabric-softening benefit, as disclosed in U.S. Pat. No. 3,607,763, Salmen et al, issued Sept. 21, 1971; and U.S. Pat. No. b 3,644,203, Lamberti et al, issued Feb. 22, 1972. Such components are also used to control static, as well as soften laundered fabrics as, for example, in U.S. Pat. No. 3,951,879, Wixon, issued Apr. 20, 1976; and U.S. Pat. No. 3,959,157, Inamorato, issued May 25, 1976. All of the above patents being incorporated herein by reference. However, none of these patents indicate that by the careful selection and combination of certain nonionic and cationic surfactants, to achieve specific nonionic:cationic surfactant ratios and reduced cationic monomer concentrations, outstanding removal of particulate soils may be obtained.
The compositions of the present invention have outstanding cleaning capabilities. In laundry tests, these compositions, not containing any builder components, have been shown to remove clay soils at least as well, and in some cases dramatically better, than fully-built conventional laundry detergent compositions. In addition, the compositions inhibit the transfer of dyes, soften and control static through the washing and drying operations. Further, by selecting the preferred cationic components defined in this application, the compositions additionally provide biodegradability and excellent removal of greasy and oily soils, while also providing, in a single detergent product, particulate soil removal, fabric softening, static control and dye transfer inhibition benefits to the laundered fabrics. The cleaning performance, which is superior to that previously demonstrated, is the result of a heretofore unrecognized cleaning potential of certain selected cationic surfactants when used in the presence of certain selected nonionic surfactants under the conditions specified herein.
It is an object of this invention to provide laundry detergent compositions which yield outstanding particulate soil removal, and which also provide fabric softening, static control and dye transfer inhibition benefits.
It is another object of this invention to provide laundry detergent compositions, yielding excellent particulate soil removal, which may be used in a variety of physical forms, such as liquid, solid, paste, granular, powder, or in conjunction with a carrier such as a substrate.
It is a further more specific object of this invention to provide specific detergent compositions which yield excellent particulate soil removal and which are biodegradable.
It is a still further specific object of this invention to define specific novel cationic surfactants which are biodegradable and which yield excellent particulate and greasy and oily soil removal performance, as well as fabric softening and static control, in the cationic/nonionic surfactant systems of the present invention.
It is another specific object of this invention to provide amide-containing cationic/nonionic surfactant-containing compositions which yield both excellent particulate soil removal and anti-redeposition properties.
It is yet another object of this invention to provide a process for laundering fabrics which yields especially good particulate soil removal, using cationic and nonionic surfactant-containing detergent compositions.